Labeling, Marking and Placarding Your Aircraft

Phil Dietro was kind enough to provide me with photographs of the labeling, marking and placarding he did while preparing his PPC for the Experimental Light-Sport (ELSA) airworthiness inspection. This is an excellent example of the various things you will need to do to prepare your aircraft. While this is for a PPC, many if not most, of these things will need to be marked for other categories of aircraft. Certain things will vary depending on the engine you have or the particular list of instruments and other equipment that is installed. 

Every aircraft must have an aircraft identification plate and registration number (N Number) markings. The FAA regulations specify what materials, sizes and locations you must use for these. See the end of this document for links to the FAA material and rules. Phil has used the I.D. plate from the EAA kit. This must be engraved or stamped with the builder, model  and serial number information that you submitted in your paperwork to the FAA. Note how he has met the requirement for permanently affixing them by providing a plate and riveting it in place. If you are worried about putting holes in a structural member you could create a clamp or strap type fixture that goes around the member and rivet the plate to that. Note the plate for the required N number on the other side. It does not have an I.D. plate affixed to it as only one is required per aircraft. Nice job matching the frame color.

N Number and I.D. Plate

The experimental sticker must be visible to people entering the aircraft. This means that most people will need two of them. Note that the EAA kit only contains one. So to save yourself extra time and shipping costs, and be sure to order an extra one when you order the kit.


This overall view of his PPC shows the N Number location (There is one on each side), and the "EXPERIMENTAL" decal that must be visible at each entry to the aircraft (Also one on each side).

Overall View

This photo shows the marking of the primer and throttle. You must provide markings that indicate what everything is and how to operate it. Note the label machine labels. These are handy for things that you cannot find preprinted labels for.

Throttle and Primer

Each experimental aircraft must have a passenger warning placard displayed where the passenger can see it. Note that the placard is specific for the Experimental Light-Sport Aircraft. A different placard must be used for an aircraft that is registered as Experimental Amateur-Built. The EAA kit is for ELSA so if you go Exp. AB you will need to obtain a separate placard. This placard and the registration number are usually affixed to the instrument panel, but here he has used an available tube to serve the purpose because no panel space exists.

Passenger Warning Placard and Registration Number (N Number)

The airworthiness certificate (Once the FAA issues it to you), must be displayed in full view. Phil has securely attached a clear vinyl pouch, with a closure method, to the aircraft. Make sure that any attachment method you use is secure. We don't want to use the prop as a document shredder.

Airworthiness certificate

Depending on the engine type you have, you may need this label. This is for a water cooled engine. Good location, hard to miss.

Check Coolant

It is good, and in most cases required, to label anything and everything, as though an idiot was going to get in your machine and operate it. Another good location that ties in with the previous one.

Coolant Type

The typical PPC has limited instrument panel space as shown in this photo. Most of them use an electronic engine monitoring system like the one shown here. This means they don't have a place on each instrument, to place the required range markings, as you do with separate mechanical instruments. It is still important to indicate the operating ranges and limits for things like coolant, CHT and EGT temperatures and RPM's. He has done this below the EIS. The EIS should also be set to produce an alarm for all available out of range conditions. Phil has labeled the panel with his N Number, he has made sure the ignition switch was labeled and shown the start location for it. The factory has labeled the power point, the instrument switch and the 2 mag switches. Phil has marked the on and off positions for the mags and provided a handy way to operate them independently or separately with a piece of tubing. A fixed wing aircraft with an instrument panel will have a few more things to mark and any mechanical instruments will require range markings.

Instrument Panel Markings

Here's a better shot of the primer. Note how he uses an arrow to indicate it's exact location.


The required fuel grade and quantity needs to be marked on the tank near the filler cap. Phil has used a premade label and then attached his specific requirements to it with a label maker.

Fuel Grade and Quantity

If you can't read this it says "Radiator Louver Pull to close Push to open", and has an arrow indicating direction. This is another example of labeling everything and indicating how it operates.

Radiator Louver

Here's a close-up.

Radiator Louver


Tandem seat aircraft need this marking so that a proper weight and balance may be maintained and so a solo pilot has all the necessary controls available to operate the aircraft.

Solo Flight Front Seat Only

Aircraft with oil injection engines need this marking. Aircraft with engines that use premixed oil and gas should have a marking indicating this near the filler. It should indicate the oil type and mix ratio.

Oil Injection/2-Cycle Oil

Oil injection tank levels should be indicated as shown in the photo. He's using that handy label maker again.

Oil Levels

Some more things to think about

Preparing your Aircraft for Inspection
You will need to prepare your aircraft for an airworthiness inspection. This inspection involves the physical condition of the aircraft as well as required markings and equipment.
Many of us have aircraft that need work to bring our aircraft into a condition that is considered airworthy. This is an opportunity to make your aircraft safer. I recommend you do all the things necessary to put your aircraft in condition for safe flight. In addition, I recommend that you make any modifications before getting it inspected. Most modifications are considered major alterations and require FAA paperwork and inspections and even a test flight period. It is easier to do the work now in a less regulatory environment. If you intend to change an engine then be sure to submit the serial number of the new engine on your registration information.
In addition to improving the general condition of your aircraft, the FAA has requirements for the markings of your aircraft as well as equipment that will have to be installed. You may also want to consider installing the equipment necessary to use your aircraft for your Practical Test (If a 2-seater). It is optional for the DPE (Designated Pilot Examiner) to use your ELSA (Experimental Light Sport Aircraft) for the Practical Test, so check to see if he will.

Note: When attaching I.D. plates, placards or equipment, be careful not to damage or compromise structural members of the aircraft with bolt holes. Affix with straps or other methods wherever possible. Another thing to look out for concerns the actual markings and ID plates and other materials you use. Equipment suppliers sell items that seem to be what you need but don't meet FAA requirements. For instance, you need a fireproof (steel or S.S.) ID plate. Aluminum won't do. The plate should say Amateur Built for AB Exp. and Light Sport for ELSA. The passenger warning placard reads differently too. You don't need TSO'd equipment for experimental aircraft but when picking things like strobes and lighting and such the FAA approved items might be better quality. They might also be too heavy and expensive. It's your call.

There are a number of ways that you will need to mark and identify your aircraft to meet the FAA requirements. You will need to provide Identification and registration markings, instrument markings and general equipment marking. You will also have to install an I.D. plate for your aircraft. In general, every device should be labeled and every control should have all of the operating positions labeled.
Many of the aircraft supply companies have kits for the marking of aircraft. The marking of Exp. AB will be similar to Experimental Light Sport but there will be differences. Check Part 45.

Other Information

Identification and Registration Markings
The FAA requirements for identification and registration markings are detailed in FAA Advisory Circular AC45-2B here:

AC45-2B Identification and Registration Marking

Instrument Markings
Here is some helpful information on requirements:

AC20-88A Guidelines on the Marking of Aircraft Powerplant Instruments (Displays)

Aircraft Certification

I have created a website for UL pilots transitioning themselves and their aircraft to Sport Pilot. The site is here:

Sport Pilot Training

It contains a guide to N Numbering, registering and obtaining an airworthiness certificate for your aircraft. It is here:

Sport Pilot Aircraft Certification Guide


Each aircraft has specific needs for marking, labeling and placarding. If you carefully follow the FAA's requirements, and go by the general rule that everything needs to be labeled with what it is and how it operates, you will go a long way toward completing the process of preparing your aircraft for the airworthiness inspection. This page is meant to be a general guide. If you have any questions about particular items it would be a good idea to contact the DAR or FAA inspector who will be conducting the inspection on your aircraft. Ask them what they expect before hand so things go smoothly on inspection day. Good luck.


Without the help of Phil Dietro this page wouldn't exist. It was his idea, and his excellent photos are the basis for it. He is a Sport Pilot Flight Instructor PPC Land and an UFIE (Ultralight Flight Instructor Examiner) under the EAA (Experimental Aircraft Association) exemption. If you would like to contact him here is his contact info:

Phil Dietro, UFIE, SP CFI ,PPL.
Inland Paraflite, Inc.

(760) 242-3359